Stoker



R. C. RIVERS Nov. 26, 1968 STOKER Filed March 30, 196

RUSSELL Cv RIVERS INVENTOR.

R. C. RIVERS Nov. 26, 1968 STOKER 2 Sheets-Sheet 2 Filed March 30, 1967 FIG. 2

FIG. 3

RUSSELL C. RIVERS INVENTOR.

United States Patent 3,412,698 ST OKER Russell C. Rivers, Boylston, Mass., assignor to Riley Stoker Corporation, Worcester, Mass., a corporation of Massachusetts Filed Mar. 30, 1967, Ser. No. 627,030 6 Claims. (Cl. 110-40) ABSTRACT OF THE DISCLOSURE This invention relates to a stoker and, more particularly, to apparatus for burning solid fuel in an incinerator or the like, wherein the space under the grate is divided into compartments and each compartment carries an inclined trough there being water sprays to carry siftings into a disposal system.

It is common practice to use a traveling grate stoker for the burning of trash in a municipal incinerator. One of the difiiculties encountered, however, is that the trash contains considerable amounts of materials such as aluminum foil which melt at low temperature. In the case of the aluminum, it melts on the upper grate surface, flows in liquid form through the grates, and lands in the lower run of the stoker where it solidifies and interferes with the mechanical operation of the stoker. There is also a tendency for ash to sift through onto the lower run and this must be removed by hoeing. Another problem that is experienced is that it is difficult to maintain even air fiow through the grate surfaces; there is a tendency for the air which is closest to the air supply ducts to receive most of the air, while the grates which are a considerable distance from them are starved. The result can be that the fuel on one side of the grate can burn out properly while that on the other side does not. These and other difiiculties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide a stoker having a means for catching and removing siftings as they fall through the grate.

Another object of this invention is the provision of a stoker for use in burning trash, wherein molten materials are prevented from falling through the grate and solidifying in the mechanical elements of the stoker.

A further object of the present invention is the provision of a stoker in which means is provided for assuring even flow of air through the various portions of the grate surface.

It is another object of the instant invention to provide a stoker having means for providing for siftings removal without loss of air.

It is a further object of the invention to provide a stoker having an integrated air and siftings removal system which is balanced so that the operation of one side of the stoker is not appreciably different from the operation of the other side.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to one of its structural forms as illustrated by the accompanying drawings in which:

FIG. 1 is a plan view of a stoker embodying the principles of the present invention,

FIG. 2 is a vertical sectional view of the invention taken on the line II-II of FIG. 1, and

FIG. 3 is a vertical sectional view of the invention taken on the line IIIIII of FIG. 1.

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In general, the invention consists of providing a grate with a plenum chamber lying underneath it which is divided into a plurality of zone chambers by a number of generally-vertical walls. An inclined tray lies in each zone chamber and forms the bottom thereof; a water supply means is associated with each tray to cause a stream of water to how therealong for the removal of siftings. Furthermore, alternate walls are formed as hollow elements and provide a path from one side to another of the grate, some of the zone chambers being supplied with air directly from an air chamber and the remainder of the zone chambers being provided with air at the other side of the grate from the said hollow walls.

Referring first to FIG. 1, wherein are best shown the general features of the invention, the stoker, indicated generally by the reference numeral 10, is shown as consisting of a grate 11 which is of the continuous-loop type having an upper run and a lower run extending in spaced, parallel relationship and mounted on shafts 12 and 13 at its opposite ends. The shaft 12 is driven by a motor 14. An air chamber 15 exetnds along one side of the grate and is provided with air from ducts 16, 17, and 18. The runs of the grate 11 define a plenum chamber which is divided into a plurality of zone chambers by generally vertical walls 19, 21, 22, 23, 24, 25, and 26. The walls 21, 23, and 25 are hollow and lead from the air chamber 15 into secondary air chambers 27, 28, and 29, respectively. The walls 19 and 21 define a zone chamber 31; walls 21 and 22 define a zone chamber 32; walls 22 and 23 define a zone chamber 33; walls 23 and 24 define a zone chamber 34; walls 24 and 25 define a zone chamber 35; while walls 25 and 26 define a zone chamber 36. Air flow from the air chamber 15 into the zone chamber 31 is regulated by a damper 37 at one side of the grate. Air flow from the air chamber 15 into the zone chamber 33 is regulated by a damper 38, and air flow from the air chamber 15 into the zone chamber 35 is regulated by a damper 39. At the other side of the grate air flow from the secondary air chamber 27 into the zone chamber 32 is regulated by a damper 41. Air flow from the secondary air chamber 28 into the zone chamber 34 is regulated by a damper 42; and air flow from the secondary air chamber 29 into the zone chamber 36 is regulated by a damper 43. Each of the zone chambers is connected at the end opposite the end from which the air arrives into a sewer system 44 having a tank 45. This is accomplished in the case of the zone chamber 31 by a conduit 46, the zone chamber 32 by a conduit 47, the zone chamber 33 by a conduit 48, the zone chamber 34 by a conduit 49, the zone chamber 35 by a conduit 51, and the zone chamber 36 by a conduit 52.

Referring now to FIG. 2, it can be seen that the duct 16 arrives from below to introduce air into the air chamber 15. The air chamber 15 is separated from the zone chamber 31 by a wall 53 having an aperture 54. The air flowing through the aperture is controlled by a damper plate 55 forming part of the damper 37. The damper 37 is of the type shown and described in my patent application Serial Number 558,195, filed May 31, 1966. As is evident in the drawing, the grate 11 consists of an upper run 56 and a lower run 57 which define between them the plenum chamber 58 of which the zone chamber 31 is a portion. The bottom of the zone chamber 31 is provided with a tray 59 which is inclined transversely of the grate and extends from the level of the bottom edge of the aperture 54 on one side to the level of the pipe 46 at the other side. Overlying the tray are water pipes 61 which are provided with nozzles directed downwardly toward the tray to provide a continuous flow of water from one end to the other into the pipe 46. The nozzles spread the water so that a sheet of water covers the bottom of the tray at all times.

As is evident in FIG. 2, the ends of the sewer system 44 extend below the level of the water 62 in the tank 45. This level is maintained at a substantially constant height by continuous introduction and overflow of water.

Referring now to FIG. 3, it can be seen that the walls 19, 21, 22, 23, 24, 25, and 26 are formed as I-beams having very long webs. These I-beams form the structural support for the stoker and, of course, extend parallel to one another across the stoker. In the case of the walls 21, 23, and 25 it can be seen that they are made up of two of these I-beams having their adjacent flanges close together to provide a closed duct of rectangular cross section. Each hollow duct extends from one side to the other of the grate from the chamber 15 to the secondary chambers. For instance, the wall 21 is formed of two I-beams 63 and 64 and the hollow duct formed by them extends from the air chamber 15 into the secondary air chamber 27.

The operation of the stoker will now be readily understood, in view of the above description. With the motor 14 operating, the shaft 12 drives the grate so that the upper run 56 moves toward the shaft 13 and the lower run 57 moves from the shaft 13 toward the shaft 12. Fuel in the form of refuse is introduced onto the grate in the area above the shaft 14 and moves rearwardly along the grate. Air is introduced through the ducts 16, 17, and 18, so that the chamber 15 is well supplied with heated air under a pressure. The flow of air into the zone chambers 31, 33, and 35 is regulated by the dampers 37, 38, and 39, respectively, the air coming directly from the chamber 15 into the zone chambers. The air for the zone chamber 32 passes through the wall 21 in the duct-like space provided thereby into the secondary chamber 27. It then flows through the damper 41 into the zone chamber 32. The zone chamber 34 is similarly provided with air through the medium of the hollow wall 23 and the secondary chamber 28, while the zone chamber 36 is provided with air through the wall 25 and the secondary chamber 29. During the burning of the refuse on the upper run 56 of the grate, the material is capable of melting at the ternperatures used and can pass through the grate and fall on the water-covered tray underlying it. If a globule of molten aluminum falls through the grate into the zone chamber 31, it will fall onto the tray 59 which is being supplied with a continuous fiow of water. The globule will immediately solidify and be carried by the flow of water into the pipe 46 and, eventually, into the tank 45 where it will lie on the bottom and later be decanted. Air will not escape through the pipe 46 from the zone chamber 31 which may be under substantial air pressure because the end of the sewer system underlies the level of water in the tank 45 by a substantial amount, thus providing a water seal for the system. It can be seen in every case that the removal of the sittings with the water takes place at the end opposite the end of the zone chamber at which the air is introduced. Since the chamber 31 is provided with air directly from the air chamber 15, it is natural to suppose that those grates which lie most closely adjacent the air chamber 15 would receive the most air, while the grates at the other end adjacent the pipe 46 would be starved for air. This is compensated for, however, by the fact that when the burnable material arrives on the upper run 56 in the portion overlying the zone chamber 32, the zone chamber 32 is provided with air from the secondary chamber 27 and it will be natural to assume that the grates most closely adjacent the sec ondary air chamber 27 would receive the most air, while that at the other end adjacent the pipe 46 would receive less air. This, of course, is not always true because of the fact that in an incinerator the fuel arrives sporadically and is not evenly distributed over the upper surface of the grate. However, all things being equal, the distribution of air in this method will assure the most even burning of fuel from one end of the grate to the other and from one side to the other.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent is:

1. A stocker, comprising (a) a grate having a plenum chamber therebeneath,

(b) a series of generally-vertical walls underlying the grate and dividing the plenum chamber into a plurality of zone chambers,

(c) an inclined tray lying in each zone chamber and forming a bottom therefor,

(d) a water supply means associated with each tray and causing a stream of water to flow therealong for the removal of siftings, and

(e) an air chamber extending along one side of the grate, alternate walls being hollow and providing a. path from one side to another of the grate, means being provided whereby some of the zone chambers are supplied with air directly from the air chamber and the remainder of the zone chambers are provided with air at the other side of the grate from the said hollow alternate walls.

2. A stoker as recited in claim 1, wherein the trays in the zone chambers which are supplied with air from the hollow walls are inclined to drain toward the said one side of the grate while the trays in the zone chambers which are supplied with air directly from the air chamber are inclined to drain toward the said other side of the grate.

3. A stoker as recited in claim 1, wherein the grate has a generally horizontal upper surface of rectangular conformation, the walls extending transversely thereof.

4. A stoker as recited in claim 1, wherein the grate is of the continuous looped type having an upper run and a lower run extending in spaced, parallel relationship, the upper and lower limits of the plenum chamber being defined by the runs.

5. A stoker as recited in claim 1, wherein the lower end of each inclined tray is connected by a conduit to a sewer.

6. A stoker as recited in claim 5, wherein a constant water level is maintained in the sewer and the conduit extends below its surface to act as an air seal.

References Cited UNITED STATES PATENTS 1,741,808 12/1929 Bennis 1l040 2,662,763 12/1953 Heaps et a1. 1l0-l71 X JAMES W. WESTHAVER, Primary Examiner. 

